<!DOCTYPE html>
<html>
	
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			.div1 {
				width: 100px;
				height: 100px;
				background: red;
				position: relative;


			}

			.div2 {
				width: 100px;
				height: 100px;
				background: blue;
				position: relative;
				z-index: 10;

			}

			.per {
				width: 200px;
				height: 200px;
				background: green;
				position: relative;
				z-index: 11;
				top: -50px;
			}

			.test {
				width: 100px;
				height: 100px;
				background: #ccc;
				position: relative;
				z-index: 1;
			}
		</style>
	</head>
	<body>
		<div class="div1"></div>
		<div class="div2"></div>
		<div class="per">
			<div class="test"></div>
		</div>
	</body>
</html>
